Apparatus and method for producing synthetic torque yarn

ABSTRACT

Apparatus for the production of synthetic torque yarn including a twist arresting ring disposed between a traveler assembly and a heating element to impound twists formed in yarn delivered to the traveler assembly from a supply such that the twists are heated by the heating element and such that the yarn is then wound on a spindle by the traveler assembly. A method for producing a synthetic torque yarn including the step of engaging yarn with a twist arresting ring disposed between a traveler assembly and a supply to impound twists in the yarn between the ring and the supply.

United States Patent 1 3,683,612 Buzano 1 Aug. 15, 1972 [54] APPARATUS AND METHOD FOR 3,032,961 5/1962 Delesalle ..57/106 X PRODUCING SYNTHETIC TORQUE 3,095,688 7/1963 Russell ..57/106 YARN 3,435,607 4/1969 Bowers et al ..57/34 HS X [72] Inventor: Michel Bqzano, 17, Chemin 3,316,703 5/1967 McKelvle ..57/106 ghateau Gaillard 69, vllleurbanne, Primary Examiner Donald E. Watkins rance AttorneySherman and Shalloway [22] Filed: Dec. 4, 1970 [2]] Appl. N0.: 95,013 [57] ABS CT Apparatus for the production of synthetic torque yarn including a twist arresting ring disposed between a gfig gi 32 traveler assembly and a heating element to impound [5H Int Cl 7/52 b 13/08 twists formed in yam delivered to the traveler as- I Fie'ld P 36 34 51 6 66 sembly from a supply such that the twists are heated 57/75 4 6 I 6 by the heating element and such that the yarn is then wound on a spindle by the traveler assembly. A l 56] References Cited method for producing a synthetic torque yarn including the step of engaging yarn with a twist arresting ring UNITED STATES PATENTS disposed between a traveler assembly and a supply to 2 473 520 6/1949 ey 57/106 X impound IWISIS in the yarn between the ring and the on I 2,867,075 1/1959 Reissmuller ..57/106 Supp y 2,932,152 4/ 1960 Jackson ..57/66 10 Claims, 4 Drawing Figures APPARATUS AND METHOD FOR PRODUCING SYNTHETIC TORQUE YARN BACKGROUND OF THE INVENTION 1. Field of Invention The present invention pertains to the production of synthetic torque yarn and, more particularly, to a method and apparatus for producing such yarn by accumulation of twist.

2. Discussion of the Prior Art Synthetic torque yarns are utilized to a great extent in the garment industry, especially in the manufacture of hosiery and other knitted apparel. Such yarns have a residual torsion couple, and it will be appreciated that alternate knitting of a course of yarn having a residual S twist or torsion couple with a course of yarn having a residual Z twist or torsion couple will provide an excellent product. Thus, it may be seen that yarns of low elasticity may be utilized to obtain an extremely elastic knit.

Various methods and apparatus have been proposed for the manufacture of such torque yarns by providing the yarn with a false twist.

Furthermore, conventional false twist production has the disadvantage of limiting the rate of production at an undesirably low level. False twisting methods have been proposed utilizing friction and pneumatic means to provide the false twist; however, when friction is utilized, the element providing the friction tends to wear very quickly and, with pneumatic methods, the air consumption is a distinct disadvantage.

Another proposed method to produce such torque yarn is by accumulation of twist and is effected by as sembling and disassembling yarns. The disassembling operation, which must be utilized with such methods, is extremely difficult to effect and involves complex solutions and, therefore, has not been well received in the textile field.

It is well know in the textile field that a predetermined twist can be imparted to yarn by winding the yarn with a traveler assembly. A conventional traveler assembly normally includes a ring with a spindle extending therethrough and a traveler adapted to move around the ring to wind yarn onto the spindle. The twisting provided by such a traveler assembly is slight but is adequate to ensure necessary cohesion in certain textile applications. It has been proposed to impound the twists in a yarn on the traveler; however, such impounding requires a specially designed traveler assembly wherein the traveler has a sharp edge to deform the yarn. One problem with the use of such a traveler assembly to impound the twist in a yarn is that it is extremely difficult to control the rotation of the traveler on the ring and, therefore, differences in tension occur during the winding operation with the traveler assembly.

Reference is made to U. S. Pat. No. 3,001,355 to Evans and U. S. Pat. No. 3,425,607 to Bowers, et al, which patents are exemplary of prior art method and apparatus for producing torque yarn as above described.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to utilize a conventional traveler assembly which causes no deformation of yarn in the production of a synthetic torque yarn.

The present invention is generally characterized in a method for the production of synthetic torque yarn including the steps of delivering a yarn from a supply to a traveler assembly, winding the yarn onto a spindle at the traveler assembly to twist the yarn, and engaging the yarn with a twist arresting ring disposed between the traveler assembly and the supply to impound the twists in the yarn between the twist arresting ring and the supply. The present invention is further generally characterized in apparatus for effecting the above method.

Another object of the present invention is to utilize a twist arresting ring disposed between a conventional traveler assembly and a supply of yarn to impound twists in the yarn between the twist arresting ring and the supply.

A further object of the present invention is to provide a method of producing synthetic torque yarn with constant tension.

Some of the advantages of the present invention over the prior art are that conventional traveler assemblies may be utilized therewith and that the tension of the yarn as it is rotated in the traveler assembly is extremely low.

Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic elevation of apparatus for producing synthetic torque yarn in accordance with the present invention.

FIG. 2 is a schematic elevation of a modification of the apparatus of FIG. 1 wherein the yarn is drawn prior to introduction into the apparatus.

FIG. 3 is a broken elevation of the traveler assembly and twist arresting ring of the apparatus of FIGS. 1 and 2.

FIG. 4 is a schematic representation of an assembly utilized to determine the value or torsion couple of the torque yarn.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Apparatus for the production of synthetic torque yarn in accordance with the present invention is illustrated schematically in FIG. 1 and includes a package of yarn 10 such as is conventionally wound on a bobbin or cone. The yarn 12 is drawn from the package 10 over a pin or bar guide 14 to a pair of feed rollers 16. The yarn, as supplied by package 10, has not been drawn; however, as will be appreciated from the description of the apparatus in FIG. 2, the drawing apparatus illustrated in FIG. 1 is not necessary to the present invention in that the yarn 12 could be supplied after being subjected to a drawing process.

From feed rollers 16 the yarn 12 passes over a draw pin or drawing finger 18 to a draw godet including rolls 20 and 22. From roll 22 the yarn passes adjacent a plate-type heating element 24 and through a guide loop 26 to a take-up assembly such as the traveler assembly generally indicated at 28. Traveler assembly 28 is of conventional structure and includes a ring 30 carrying a traveler 32 through which yarn 12 extends, the

traveler being adapted to move around the ring 30. A

spindle 34 extends axially through ring 30, and the spindle and traveler assembly may be driven in a conventional manner.

A twist arresting ring 36 is disposed in spaced parallel relation to ring 30 of traveler assembly 28 between the traveler assembly and the supply of yarn. It is important that ring 36 be disposed such as to impound twists in the yarn at a position between heating element 24 and traveler assembly 28 as will be appreciated from the following discussion. The yarn l2 bends slightly around the twist arresting ring 36 as it is taken up on spindle 34 and the engagement of the yarn with ring 36 impounds twists caused by the movement of the traveler 32 around ring 30 between the twist arresting ring and the supply.

In the embodiment of FIG. 2, a modification of the apparatus of FIG. 1 is illustrated wherein the yarn has been drawn prior to introduction to the apparatus such that a yam package 38 supplies previously drawn yam to feed rollers 16 through a guide loop 39. Thus, it will be appreciated that the twisting and impounding structure of the embodiment of FIG. 2 is identical to that of FIG. I with the exclusion of the drawing apparatus; and, accordingly, identical reference numbers are utilized to identify parts in the embodiment of FIG. 3, which are identical to parts in the embodiment of FIG. 1.

The structure and function of the twist arresting ring 36 will be better understood with reference to FIG. 3 wherein it can be seen that twist arresting ring 36 is annular and has a concave surface 40 oriented to engage the yarn 12 as it passes thereby to cause the yarn to bend around the ring. Twist arresting ring 36 is supported on a base 41 of the traveler assembly by a plurality of arms 43 and has an inner diameter smaller than the inner diameter of traveler ring 30. As the traveler 32 moves around traveler ring 30, a balloon 42 is formed with a curvature extending substantially between twist arresting ring 36 and guide loop 26. Once the yarn passes twist arresting ring 36, it experiences a bending motion such that it curves in an opposite direction 44 to the curve of balloon 42 to be received by traveler 32. Guide loop 26 is maintained at a specific distance from twist arresting ring 36 and traveler assembly 28 by means of an L-shaped support arm 46 which is rigidly secured to the base 41 of the traveler assembly 28. Loop 26 has a diameter sufliciently large to permit balloon 42 to be formed with a large diameter.

In operation, as yarn 12 is wound on spindle 34, it is twisted and the twists are impounded upstream of twist arresting ring 36 such that they build up to a position adjacent the supply, which position may be defined as the exit of yarn from the draw godet in the apparatus of FIG. 1 or the exit of yarn from feed rollers 16 in the apparatus of FIG. 2. The twists in the yarn are, therefore, subjected to heat setting due to the proximity to heating element 24 as they pass thereby. The number of twists impounded upstream of the twist arresting ring 36 is dependent on the characteristics of the ring 36. This number of twists remains practically constant and when it is reached, the yarn is then wound on spindle 34 with the winding twist given by the rotation of the traveller on the ring.

Example Using the apparatus of FIG. 1, a polyhexamethylene adipamide yarn (nylon 66) 92 dtex two strands was treated. The operative conditions were as follows:

draw rate 585 m/min level of drawing 4.2

temperature of the heating plate 280C diameter of the twist arresting ring (36) 127 mm distance between the lower part of the twist arresting ring (36) and the upper part of the traveler ring (30) I I7 mm distance between the twist arresting ring (36) and the guide loop (26) 350 mm rate of rotation of the spindle (34) 7700 rpm balloon tension above the twist arresting ring (36) 3 -4 g The traveler assembly used was of a standard type. The residual torsion couple as the material came from the apparatus was 580 and when stabilized after 24 hours was 300.

The torsion couple was measured in the following way:

a 2 meter length of yarn was attached at one end to a fixed point A in the assembly of FIG. 4. The yarn was passed over a hook at point B positioned one meter below point A and the other end of the yarn was fixed to point A.

The yarn was then freed at point B by removing the hook, and due to the effect of the residual torsion couple the yarn began to twist. Using a torsiometer of known type, the binding torsion between two strands of the yarn was then counted.

In order to demonstrate the elasticity of a knot made from this yarn, a yarn with S twist and a yarn with Z twist were prepared in the same operative conditions. Only the direction of rotation of spindle 34 was changed, and a stocking was made as follows:

On a circular double drop 420 needle knitter with diameter 9.525 cm (3 inches), a jersey textile was knitted to form a stocking by alternating a course of S twist yarn with a course of Z twist yarn to yield a grey stocking. The stocking was fixed at 100 C for 20 minutes, then dyed at C for 3 hours and blocked at 125 C for seconds.

As the stocking dropped from the knitter, a length of mm was marked with the stocking laid flat in a relaxed state. Then the stocking, before any heat treatment, was threaded onto a cylindrical tube 80 mm in diameter and on its free end a weight of 1 kg was suspended, and elongation in the grey state was measured. The same measurement was repeated on the blocked stocking. Finally the load was released and the stocking was once more laid flat and the distance separating the marks which originally were 100 mm apart was measured, this distance being called the return distance.

The above was repeated with application of a 300 g load instead of the 1 kg load.

The results are as follows:

% elongation 1 kg return dis- 300 g load load tance in mm grey stocking 210 260 blocked stocking I75 235 105 Finally the maximum elasticity or elongation of the stocking was determined.

The results were as follows:

relaxed maximum length taken length elongation up by the in mm in mm stocking after maximum elongation in mm grey stocking 37 1 18 43 blocked stocking 42 I07 45 It should be noted that the stocking presents a very great elasticity and that even when it is subjected to a great stress which causes maximum elongation it returns, after removal of the elongation stress, to a length very close to the original length.

The testing steps described in the above example were repeated utilizing a pre-drawn yarn treated with the apparatus of FIG. 2, and the results obtained were substantially the same as those in the above example.

From the above, it will be appreciated that by utilizing a twist arresting ring to contact or engage yarn at a position upstream of a take-up assembly, the yarn will be wound on a spindle, and the twists in the yarn will be impounded by the twist arresting ring such that the twists are exposed to the heat from a heating element.

Accordingly, the method and apparatus of the present invention produce torque yarn having a high residual torsion couple at a high speed with a conventional takeup assembly, such as a ring and traveler. The concave surface of the twist arresting ring effectively irnpounds the twists upstream of the twist arresting ring without deformation of the cross-sectional configuration of the yarn. I

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter described in the specification or shown in the drawings be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A method for the production of synthetic torque yarn comprising the steps of delivering a yarn from a supply to a take-up assembly, winding the yarn onto a spindle at the take-up assembly to twist the yarn; and engaging the yarn with a twist arresting ring disposed between the take-up assembly and the supply to irnpound the twists in the yarn between the twist arresting ring and the supply.

2. The method as recited in claim 1 and further including heating the impounded twists in the yarn.

3. The method as recited in claim 2 wherein said engaging step includes bending the yarn around the twist arresting ring.

4. The method as recited in claim 3 wherein said delivering step includes the step of drawing the yarn.

5. ln apparatus for producing a synthetic torque yam including a supply of drawn yarn, a take-up assembly for winding the yarn on a spindle and twisting the yarn and heating means disposed between said take-up assembly and said supply and adjacent the path of travel of the yarn from said supply to said take-up assembly, the improvement comprising a twist arresting ring disposed between said take-up assembly and said heating means in a position to engage the yarn and impound twists in the yarn between the twis arresting ring and the supply and adjacent the heating means.

6. The apparatus as recited in claim 5 wherein said twist arresting ring has a concave surface engaging the 'W The apparatus as recited in claim 5 wherein said take-up assembly includes a traveler assembly having a base, a traveler ring supported on said base and a traveler movable around said traveler ring to wind the yarn on the spindle, and said twist arresting ring is supported on said base in spaced parallel relation to said traveler ring.

8. The apparatus as recited in claim 7 wherein a stationary guide loop is positioned between said twist arresting ring and said heating means and supported by an arm secured to said base of said traveler assembly, the yarn passing through said guide loop to said traveler.

9. The apparatus as recited in claim 8 wherein the inner diameter of said traveler ring is greater than the inner diameter of said twist arresting ring whereby the yarn bends around said twist arresting ring.

10. The apparatus as recited in claim 9 wherein said twist arresting ring has a concave surface engaging the yarn. 

1. A method for the production of synthetic torque yarn comprising the steps of deLivering a yarn from a supply to a take-up assembly, winding the yarn onto a spindle at the take-up assembly to twist the yarn; and engaging the yarn with a twist arresting ring disposed between the take-up assembly and the supply to impound the twists in the yarn between the twist arresting ring and the supply.
 2. The method as recited in claim 1 and further including heating the impounded twists in the yarn.
 3. The method as recited in claim 2 wherein said engaging step includes bending the yarn around the twist arresting ring.
 4. The method as recited in claim 3 wherein said delivering step includes the step of drawing the yarn.
 5. In apparatus for producing a synthetic torque yarn including a supply of drawn yarn, a take-up assembly for winding the yarn on a spindle and twisting the yarn and heating means disposed between said take-up assembly and said supply and adjacent the path of travel of the yarn from said supply to said take-up assembly, the improvement comprising a twist arresting ring disposed between said take-up assembly and said heating means in a position to engage the yarn and impound twists in the yarn between the twist arresting ring and the supply and adjacent the heating means.
 6. The apparatus as recited in claim 5 wherein said twist arresting ring has a concave surface engaging the yarn.
 7. The apparatus as recited in claim 5 wherein said take-up assembly includes a traveler assembly having a base, a traveler ring supported on said base and a traveler movable around said traveler ring to wind the yarn on the spindle, and said twist arresting ring is supported on said base in spaced parallel relation to said traveler ring.
 8. The apparatus as recited in claim 7 wherein a stationary guide loop is positioned between said twist arresting ring and said heating means and supported by an arm secured to said base of said traveler assembly, the yarn passing through said guide loop to said traveler.
 9. The apparatus as recited in claim 8 wherein the inner diameter of said traveler ring is greater than the inner diameter of said twist arresting ring whereby the yarn bends around said twist arresting ring.
 10. The apparatus as recited in claim 9 wherein said twist arresting ring has a concave surface engaging the yarn. 